The Beaufort Gyre variation and its impacts on the Canada Basin in 2003–2012  

作　　者：ZHONG Wenli ZHAO Jinping SHI Jiuxin CAO Yong 

机构地区：[1]Key Laboratory of Physical Oceanography, Ocean University of China

出　　处：《Acta Oceanologica Sinica》2015年第7期19-31,共13页海洋学报（英文版）

基　　金：The Key Project of Chinese Natural Science Foundation under contract No.41330960;the National Basic Research Program of China under contract No.2015CB953902;the Project of Study on the seasonal halocline and near sea surface temperature maximum in Arctic under contract No.41306196

摘　　要：The Beaufort Gyre （BG） was spun up in the last decade which is an important factor in regulating the variation of the upper ocean. The heat content and freshwater content of the upper ocean increased gradually in the Canada Basin, as did momentum input. Both the geostrophic wind curl and freshwater content could contribute to the spin-up of BG. However, even though there is no change of the wind field the increasing freshwater alone could result in the spin-up of BG. In this study we show that the Pacific Water is difficult to flow into the central basin as the BG spins up and the maximum temperature of the Pacific Summer Water （PSW） experienced a dramatic decrease inside the BG in 2005 and 2009 due to a change of flow pathway of PSW. The enhancement of Ekman Pumping （EP） contributed to the deepening of the Pacific Winter Water by piling up more freshwater. This change of water column dynamics has also contributed to the deepening ofthe Atlantic Water core after 2007. The EP decreased significantly in 2012 （indicating a spin down of BG） and the direction of Ekman transport turned to the north, which favoured the release of freshwater that had resided in the basin for years.The Beaufort Gyre （BG） was spun up in the last decade which is an important factor in regulating the variation of the upper ocean. The heat content and freshwater content of the upper ocean increased gradually in the Canada Basin, as did momentum input. Both the geostrophic wind curl and freshwater content could contribute to the spin-up of BG. However, even though there is no change of the wind field the increasing freshwater alone could result in the spin-up of BG. In this study we show that the Pacific Water is difficult to flow into the central basin as the BG spins up and the maximum temperature of the Pacific Summer Water （PSW） experienced a dramatic decrease inside the BG in 2005 and 2009 due to a change of flow pathway of PSW. The enhancement of Ekman Pumping （EP） contributed to the deepening of the Pacific Winter Water by piling up more freshwater. This change of water column dynamics has also contributed to the deepening ofthe Atlantic Water core after 2007. The EP decreased significantly in 2012 （indicating a spin down of BG） and the direction of Ekman transport turned to the north, which favoured the release of freshwater that had resided in the basin for years.

关 键 词：Beaufort Gyre Ekman pumping freshwater content geostrophic current Canada Basin 

分 类 号：P731.2[天文地球—海洋科学]